Fume hood

A fume hood (sometimes called a fume cupboard or fume closet) is a type of local exhaust ventilation device that is designed to limit exposure to hazardous or toxic fumes, vapors or dusts. The device is an enclosure with a movable sash window on one side that traps and exhausts gases and particulates either out of the area (through a duct) or back into the room (through air filtration), and is most frequently used in laboratory settings.

The first fume hoods, constructed from wood and glass, were developed in the early 1900s as a measure to protect individuals from harmful gaseous reaction by-products. Later developments in the 1970s and 80s allowed for the construction of more efficient devices out of epoxy powder-coated steel and flame-retardant plastic laminates. Contemporary fume hoods are built to various standards to meet the needs of different laboratory practices, ranging from the handling of perchloric acid and radionuclides to tall floor-mounted models and models equipped with scrubber systems. Fume hoods of all types require regular maintenance to ensure the safety of users.

Most fume hoods are ducted and vent air out of the area, which constantly removes conditioned air from a room and results in major energy costs for laboratories and academic institutions. Efforts to curtail the energy use associated with fume hoods have been researched since the early 2000s, resulting in technical advances, such as variable air volume, high-performance and occupancy sensor-enabled fume hoods, as well as the promulgation of "Shut the Sash" campaigns that promote closing the window on fume hoods that are not in use to reduce the volume of air drawn from a room.